BW: At the top end of the market we've seen the values of some marques rise year on year between 10-25%. But even at the lower end of the market motorcycles have increased in value by 5-10%.

Having said that bikes have been 'cheap' for a very long time in comparison to the motor cars and people have woken up to this fact.

PFC: What advice would you give to a novice collector with an interest in motorcycles - and what sort of motorcycle is a good 'entry level investment'?

BW: My best advice is never to buy for investment. Always buy because you are going to love and enjoy owning and riding a classic motorcycle. If and when you come to sell it, and it sells for more than what the machine has cost to buy and maintain, then that is a bonus.

But, as general rule, always buy the best you can. A high level of originality, matching frame and engine with good history and documentation is most desirable.

Ben Walker: "A great bike to find would be the machine that SteveMcQueen rode in The Great Escape!

PFC: If you had to persuade a collector to put their money into classic motorcycles instead of classic cars, what would you tell them?

BW: Hopefully I wouldn't have to persuade them. Generally the car collectors have an interest and empathy with the motorcycles - and vice versa with the bike guys. And you'll find that many of the world's top car collectors' also have a collection of motorcycles.

But if I did have to persuade them, I'd say think about the storage (four or five bikes for every car space), the ease of maintenance, and what you can buy for your money! Plus they'll look great alongside the Ferrari, Bentley, Jaguar... or whatever happens to be in the garage!

PFC: Do you have a dream motorcycle that you would like the opportunity to sell?

BW: There are a number - and one day I will have the opportunity to sell them. But a great bike to find would be the machine that Steve McQueen and Bud Ekins rode in The Great Escape!

Do you have a motorcycle collection? If so, what do you ride - and which is your favourite?

BW: I do. Nine machines in total. I have a thing for British post-war twins. I've got a '59 Norton Dominator 99, a '63 BSA Rocket Gold Star and a '67 Triumph Bonneville T120R.

I've also got a fantastic '80 BMW R100S 'Exclusive Sports' - in the super rare Walter Maurer paint scheme - which I use almost on a daily basis (I know I shouldn't but it's just too good).

But one of the best machines I own is a 1979 Honda CB125S. It's never going to worth a lot, but it's very low miles, starts first time every time, and returns an extremely high mpg!